Questions - Thinking of buying a NEX

I am an casual/enthusiast (more of casual) photographer with a limited budget for photography. I have never owned a DSLR before. I do care very much for image quality although I don't pixel peep, and nor do I cry about 2mm of blown highlight in the corner of my pic. At screen-viewable size the pic must be perfect, and that's all.

What I photograph are:

My trips through various countries/cities with friends

Indoor parties

Nature, weather

And basically any shot which I see interesting. I don't pack up my camera/kit and go looking for a shot, but I'd love to have a camera and kit in my light backpack if I see one during my day.

Which is why I'm looking at the NEX-5 so longingly. The camera body is awesome, it's so perfect for my needs. Will easily slip into any pocket, low light performance is top class, IQ is very much at par with (if not better than) bulky DSLRs in its price range, it is fast and responsive, has full-time DOF/exposure preview, and so on.

The only problem is that everything from the lens mount to the flash port is non-standard.

My questions are as follows:

1) Are Tamron/Sigma/XYZ likely to come out with E mount lenses for people like me with limited budgets? Will they be AF and OSS compatible?

2) I know there are adapters for various other lens types. What adapter/lens system will give me best flexibility with shooting styles? (3rd party support necessary) Will they be AF/OSS compatible?

3) Is there a possibility of a more powerful flash being available for those difficult indoor party shots?

4) Will there be upgrades to this camera body? Or will all my lenses become useless afterwards?

5) Is the sensor cleaning system that bad?

6) Is the battery life that bad?

And finally..

7) Am I going in the right direction for my needs? Any suggestions/comments would be extremely helpful.